The statement "Vaccinations undermine a child's immune system" is roughly equivalent to the statement "Being raised by parents who are Alice Cooper fans makes a child
more likely to be shocked by Marilyn Manson". Utter crap.
If anything is going to undermine the development of a child's immune system, it's having a mother who uses antibacterial soap and hand sanitizer lotion and sprays bleach solution on every surface and yells at her kids not to eat dirt or lick trees. Immune systems are like muscles -- they get stronger from exercise and learn from repetition. If you want to raise a kid with a strong immune system, expose him to (ideally non-lethal doses) of
as many germs as possible --
vaccines included. Anyone who would warn people away from vaccines on the basis that kids should be allowed to develop "naturally" * makes me wonder if they also believe too few people die from disease every year, and that too many "weak" gene pools are being aided in surviving instead of being allowed to die off from natural selection.
* [instead of warning people away from vaccines because some may be inherently harmful, like the ones anecdotally linked to autism]
All that said, bear in mind that in flu pandemics of centuries past, a significant portion of the fatalities were college age people with strong, robust immune systems that
overreacted to the flu and ended up killing them. Had they been small children or old people with weakened immune systems, they might have lived. Damned if ya do, Damned if ya don't....
Check out this graph. The dotted line represents the age distribution of deaths from a normal 'seasonal' flu. The solid line represents the H1N1 pandemic of 1918. Normally flu mainly kills reallyreally young kids whose immune systems are physically and experientially weak, and reallyreally old folks who are just plain weak in general. But in 1918, something like 50% of the deaths were people between age 20 and 40, coz their badass immune systems didn't know when to quit.